Isolation Duration for Varicella (Chickenpox)

General Guidelines

The Centers for Disease Control and Prevention recommends that patients with varicella should remain in isolation until all lesions are crusted, which typically occurs 4-7 days after rash onset in immunocompetent individuals 1
Standard isolation duration is from 1-2 days before rash onset until all lesions have crusted over, typically 4-7 days after rash appears, as recommended by the Centers for Disease Control and Prevention 1, 2
The period of contagiousness begins 1-2 days before the onset of rash and ends when all lesions are crusted, according to the Centers for Disease Control and Prevention 1
Patients should be isolated using airborne precautions and contact precautions throughout the entire period, as recommended by the Centers for Disease Control and Prevention 2
If negative air-flow rooms are unavailable, patients should be isolated in closed rooms and avoid contact with persons without evidence of immunity to varicella, as suggested by the Centers for Disease Control and Prevention 2

Immunocompromised patients require extended isolation because they may develop progressive varicella with new lesions continuing for >7 days and remain contagious longer, according to the Centers for Disease Control and Prevention 1
Airborne and contact precautions should be maintained until all lesions are dry and crusted, which may take significantly longer than in immunocompetent hosts, as recommended by the Centers for Disease Control and Prevention 2
For immunocompromised patients with disseminated herpes zoster, isolation precautions should continue until disseminated infection is ruled out and all lesions are crusted, as suggested by the Centers for Disease Control and Prevention 2

Persons who develop progressive varicella are contagious longer due to depressed immune response allowing persistent viral replication, according to the Centers for Disease Control and Prevention 1
Healthcare personnel caring for varicella patients should have documented evidence of immunity to varicella, as recommended by the Centers for Disease Control and Prevention 2
Only healthcare personnel with evidence of immunity should provide care for patients with confirmed or suspected varicella, as suggested by the Centers for Disease Control and Prevention 2
Breakthrough varicella in vaccinated persons is contagious despite typically being milder with <50 skin lesions and shorter duration (4-6 days), according to the Centers for Disease Control and Prevention 1